Rejoice, Inc., a private foundation, has existed for 10 years. Rejoice held undistributed income of $200,400 at the end of its 2020 tax year. Of this amount, $120,240 was distributed in 2021, and $80,160 was distributed during the first quarter of 2022. The IRS mailed a deficiency notice to Rejoice on August 1, 2023, relating to the entity's undistributed income.

If amount is zero, enter "0".

a. The initial tax on the 2020 undistributed taxable income for 2021 is $______ and for 2022 is $______.

b. Select from the choices below which one properly expresses the 2021 tax computation as a Microsoft Excel formula.

c. The additional tax for 2023 relative to the 2020 income is $______?